ER11 Collet size lying?

[Philly]

I recent bought a 6-7mm collet for my 1/4" tools and my 6mm Endmills. Only theres a problem, it wont hold my 6mm endmills :(

Is this a common thing? Im not sure what size to buy for it or whether to adjust it.

Any help with be appreciated.

Thanks, Phil

[m_c]

Get a 6-5mm collet.
Either the cutters you have are slightly less than 6mm, or the tolerance of the collet is off. Either way, I've found with ER collets, it's best to use the smallest one possible for whatever you're trying to hold.

[Jonathan]

You can get a full set of adequate collets cheap enough on eBay. Bearing in mind how ER collets barely hold cutters tight enough at the best of times using a bigger collet wont help.

[m_c]

Bearing in mind how ER collets barely hold cutters tight enough at the best of times using a bigger collet wont help.

Use decent quality collets and chuck, make sure they're clean and located in the nut properly, and you shouldn't have any problems. Only time I've had problems is when I've tried to cut corners while swapping tools, and got a bit dirt in or not located them in the nut properly.

[Jonathan]

Use decent quality collets and chuck, make sure they're clean and located in the nut properly, and you shouldn't have any problems. Only time I've had problems is when I've tried to cut corners while swapping tools, and got a bit dirt in or not located them in the nut properly.

True, I wasn't giving the whole story. Also if you look at the recommended torque for the collect nut it's surprisingly large. Probably quite easy to obtain the 28Nm required for ER11. Big spanner needed for the bigger collets though - apparently it's about 105Nm for ER25 which I have on my mill.

[m_c]

Depends on the type of nut - http://www.techniksusa.com/metal/torque_chart.htm

For me with ER32 collets in the mill, I double gear it to lock the spindle, then give the collet spanner a couple good hits with my fist, which is probably a bit less than the recommended figure, but I've never had any movement issues.

[Philly]

Cheers for the help guys, I'll just have to hold the job off for a few days while I wait for the set to arrive. Good job really because I dropped the 6mm one while inspecting it and not found it yet, they have some spring in them ;)

It seemed like it may have tightened but the nut ran out of thread before it had a chance too. Not too worry, I'll be up and running soon enough.

Thanks